Download aquatic ecosystems

AQUATIC ECOSYSTEMS
SALINITY
• The types of organisms in an aquatic ecosystem
depend upon the water’s Salinity.
It's the amount of dissolved salts the water
contains.
• Salinity determines the two main aquatic
systems:
Fresh water ecosystems
Marine ecosystems
CHARACTERISTICS OF AQUATIC
ECOSYSTEMS
• Plankton – Organisms that cannot swim against
currents.
• Plankton is a Greek word which means
“wanderer" or "drifter" and it is used to describe
the class of marine plants and animals which
have limited ability or no ability to move or
"swim". They simply drift in the ocean currents
and occupy most of the surface area of the
earth's oceans. Marine means “of the ocean", so
marine plankton are organisms which can live
and grow in salt water.
TWO TYPES OF PLANKTON
• Phytoplankton are microscopic plant type
organisms. They use photosynthesis.
• Zooplankton are drifting
microscopic animal organisms.
ZOOPLANKTON
Zooplankton have one bright red eye,
travel in swarms, propel their armored
bodies through ocean currents with the
speed of a jaguar and originate from
the time of the dinosaurs.
If they weren’t smaller than 1 mm,
copepods and other zooplankton might
be considered fearsome aquatic
predators, but instead they serve as
both the low end of the food chain and
a vital warning system for global
climate change.
NEKTON
• Nekton are free-swimming organisms such as
fish, turtles, whales, etc.
• Nekton come in all shapes and sizes. They live in
shallow and deep ocean waters. Most nekton eat
zooplankton, other nektons or they scavenge for
wastes.
BENTHOS
• Benthos are bottom dwelling organisms.
• The benthos live on the ocean floor. Starfish,
oysters, clams, sea cucumbers, brittlestars and
anemone are all benthos. Most benthos feed
on food floating by or scavenge for waste on
the ocean floor.
•
FRESHWATER ECOSYSTEMS
• Lakes
• Rivers
• Wetlands – water that is periodically
underwater.
LAKES AND PONDS
• Life in a lake can be structured into zones.
Littoral Zone which is nutrient-rich, near the
shore. It has a high diversity of plants and
animals.
Benthic zone which is at the bottom of a
pond or lake. It is inhabited by decomposers,
insect larvae, and clams.
LITTORAL ZONE
BENTHIC ZONE
HOW NUTRIENTS AFFECT LAKES
• Eutrophication is an increase in the amount of
nutrients in an aquatic ecosystem.
• Usually occurs in lakes with large amounts of
algae and plant growth.
• Increased number of bacteria are present.
• The bacteria use up all the oxygen in the
water and all other organisms that need
oxygen must either move or die.
EUTROPHICATION
• Eutrophication is usually accelerated by land
run-off.
• Fertilizers get into the water system and can
cause/speed up eutrophication.
FRESHWATER WETLANDS
Two types:
1. Marshes – low, flat lands that have little water
movement
nutrient rich shallow water salinity of marshes vary
Brackish water – slightly salty
Can have as much salinity as the ocean.
ADAPTATIONS - WETLANDS
• Ducks have long bills adapted for fishing for
fish and insects.
• Herons have long beaks to grasp small fish
and to probe for frogs.
FRESHWATER WETLANDS
2. Swamps – flat, poorly drained land
Organisms adapt to the salinity and moistness of
swamps
Human impact on wetlands:
Sometimes considered wastelands for insect
breeding
• Many have been drained, filled in or cleared for
_farmland, residential/commercial development.
Example: Florida Everglades
Once covered 8 millions acres
Now 3 million acres
FRESHWATER WETLANDS
• Wetlands are actually purifiers of wastewaters
• Useful in flood prevention
• Freshwater game fish use it for feeding and
breeding.
RIVERS
Many originate from the melting waters from snow melt on
mountains.
• As water flows farther from it start, becomes warmer
and wider.
• Also gains nutrients from land runoff
Life in a river
• Plant /animal species vary depending on where rivers
are located
• Examples:
– trout – areas of strong currents, cold/oxygen-rich
waters
– catfish/carp in the deeper, calmer rivers
RIVERS
Rivers in danger
• Sewage disposal, manufacturing wastes, and pesticides
are a few of the pollutants that get into out lakes and
rivers.
• Dams alter an effect ecosystems in an around rivers.
MARINE ECOSYSTEMS
• All marine ecosystems contain saltwater.
• Coastal Wetlands
– Large habitats used for nesting birds
– Absorb excess rain-Protection from flooding.
– http://www.estuaries.gov/ (Videos)
ESTUARIES
• An estuary (pronounced es choo eree) is a
coastal area where fresh water from rivers and
streams mix with water from the ocean. Many
bayous and lagoons along coasts are estuaries.
MARINE ECOSYSTEMS
– Currents cause a mineral rich mud with dissolved
nutrients.
– Species that evolve in estuaries have adapted to the
changes and extreme conditions in their environment.
PLANTS AND ANIMALS IN ESTUARIES
 Plants and Animals of Estuaries - The community
of life found in these waters-mammals, birds, fish,
reptiles, shellfish, and plants – all represented
within complex food webs.
 Shallow areas offer a lot of light (photosynthesis).
Allows for large food webs.
THREATS TO ESTUARIES
• Threats to Estuaries
– Earlier in history they were used as solid waste
land-fills.
– Developed as building sites.
– Long considered to be wastelands, estuaries have
had their sediments dredged, marshes and tidal
flats filled, destroyed, and shorelines
reconstructed to accommodate housing,
transportation, commerce, industry,
and agricultural needs.
ESTUARIES
• Pollution damages estuaries which impacts many
organisms.
• Many species give birth in these areas.
• Estuaries have economic, natural, and aesthetic value.
People are attracted to the water and visit estuaries to
boat, fish, swim and enjoy their beauty.
• As our population grows and the demands imposed on
our natural resources increase, so too does the
importance of protecting these resources for their
natural and aesthetic values.
ESTUARIES IN THE US
SALT MARSHES
Estuaries where rivers deposit their mineral rich
mud.
Act as nurseries for many species.
Absorbs pollutants
http://www.knowitall.org/sclife/
MANGROVE SWAMPS
• Mangrove Swamps
– Species of small trees adapted for growing in
shallow salt water with above ground root
systems.
– Found in subtropical and tropical areas.
– Protect coast lines from erosion.
– Can provide habitats for over
2,000 animal species.
ROCKY AND SANDY SHORES
• Rocky Shores
• Rocks protect seaweed and many animals that
live on it. Sea anemones, mussels, sponges.
SANDY SHORES
– Life on the sandy shores is more diverse than on
rocky shores.
– Birds feed at low tide in the sand.
BARRIER ISLANDS
– Barrier islands – sandy/rocky islands that run
parallel to sandy shore lines.
– Protects land from storms and ocean waves.
CORAL REEFS
• Coral Reefs – limestone ridges built by tiny
coral animals called polyps and the algae that
live inside them.
• http://www.mbgnet.net/salt/coral/index.htm
CORAL REEFS
– Thousands of plant and animal species live in these
coral reefs.
– Most diverse habitats in the world.
– Found only in shallow tropical seas because of the
warm salty water and enough light for
photosynthesis.
CORAL REEF ANIMALS
CORAL REEFS IN DANGER
• Very fragile ecosystems
• Change in water temperature, acidity, nutrient levels can
lead to death of the algae.
• Leads to the removal of living species– coral bleaching.
• 50% of the worlds coral reefs are in danger of destruction.
• Over Fishing upsets the balance too.
• Takes a long time for coral to grow  destroyed faster than
it can regrow.
OCEANS
– Light only penetrates the ocean to about 100 m.
– All photosynthesis occurs above that line.
– Plants and Animals of Oceans
• Most organisms live near the coastal areas.
• Phytoplankton stay near the surface – the basis for
most food webs in the ocean
• At the bottom are decomposers, filter feeders, and
predators that feed on them.
THREATS TO OCEANS
– Threats to Oceans
• Fertilizer runoff  algal blooms
(red tide is poisonous)
• Over- fishing
• Ocean mammals drown while caught in nets, fishing
lines, plastics.
ARCTIC AND ANTARCTIC ECOSYSTEMS
• Diverse organisms from the plankton up to whales.
• Nutrient rich areas.